This study examined the relationship between financial institutions, insurance, and economic growth in Nigeria using an ex-post facto research design and secondary data from the Central Bank of Nigeria's Statistical Bulletin reports (2000-2022). Multiple linear regression analysis revealed that financial institutions have a significant negative impact on economic growth, with a 1% increase in Growth Rate of Public Fund Assets expected to decrease economic performance by 942.70% (β = 9.427, p = 0.013). Similarly, insurance has a significant negative impact on economic growth, with a 1% increase in insurance expected to decrease economic growth by 21973% (β = 219.73, p = 0.000). The study recommends that Nigerian financial institutions and insurance companies prudently manage and invest capital in line with regulatory guidelines and internal and external directives to ensure economic growth and sustainability.